Hi guys, I have the same problem for more than a week now... The bottom leaves are rapidly yellowing... i pick the yellow ones and new ones are introduced the next day... I though it was N deficiency but i guess it was not.. now I cut down the nutrition solution for a week now but the yellowing still is there... It may be overwatering, now I give less water... I am in the vegetation stage, I guess the last one or two weeks... please help me.. thanks SK info about the plants: I am growing in a cabinet, indoor I have two fans. one powerful exhaust and a small fan ventilating fresh air in. My watering schedule is once in every 3-4 days.. The PH is around 6.5 and the heat is around 23-28 Celcius Degrees. The humidity: around 35-55 I had planted my seeds about a month ago. And now in the "Vegetation Stage" and waiting for a couple of more weeks before going on to 12/12 flowering.. The lighting is with 8 Light Bulbs (i am using white wiselite 72Watss (5300 Lumen) each for vegetation, will then place yellow daylight ones for the flowering) For the nutrition I had used a root solution once. Now I use a "N" based vegetation solution by BioBizz
Doesn't look like nute burn to me. Nute burn usually effects the new growth shoots, not the old lower leaves.
Your watering habits: do you check the soil for dryness before watering? Do you water with enough to soak the soil all the way through? If it's overwatering that you've done, the fix is not to give it less water, it's to water less frequently. Roots must dry out between waterings. Your food: does it have all the micronutrients in it? Things like Mo, Ni, Mn, S, Zn, etc.